Endogenous pollution synergistic treatment river and lake bottom material-water body purification composite ecological carrier

Abstract

The application discloses an endogenous pollution cooperative management river and lake bottom material-water body purification composite ecological carrier, belonging to the in-situ remediation field of endogenous pollution of rivers and lakes, comprising a bottom material in-situ regulation and control matrix unit, a water body layered purification unit and a multi-source sensing cooperative regulation and control unit, and a signal and fluid communication path is formed between the units. The bottom material unit is encapsulated in a water-permeable and mud-blocking strip-shaped ecological bag, modified minerals, coated zero-valent iron slow-release electron materials and local bacterial agents are integrated to realize biological and abiological cooperative passivation degradation; modified artificial water grass is vertically coupled with the ecological bag to construct a bottom mud-water body cooperative purification link; a global layered sensor is coupled with a regulation and control algorithm to adaptively adjust hydraulic, aeration and oxygen release parameters. The carrier is modularized and assembled, is suitable for low-disturbance adaptation and dredging-restricted sensitive water areas, can simultaneously remove organic matter, nitrogen, phosphorus and heavy metals, has low operation and maintenance energy consumption, and is suitable for integrated treatment of endogenous pollution of rivers, lakes, reservoirs and estuaries.

Description

Technical Field

[0001] This invention belongs to the field of in-situ ecological restoration technology for endogenous pollution of rivers and lakes, specifically involving a composite ecological carrier for the synergistic treatment of endogenous pollution in river and lake bottom sediments and water purification. Background Technology

[0002] Eutrophication control in rivers and lakes involves two core pathways: intercepting external pollution sources and reducing internal sediment pollution. Currently, most urban rivers and lakes have completed external pollution control projects such as pipe network interception and non-point source pollution control. However, the long-term accumulation of organic matter, nitrogen, phosphorus, and heavy metals in sediment forms a stable reservoir of internal pollution. Even after effective control of external pollution inputs, nutrients in the sediment pore water continue to diffuse and be released into the overlying water bodies, becoming a core cause of long-term eutrophication and seasonal cyanobacterial blooms. Currently, sediment remediation and water purification technologies are developed and implemented independently, lacking a synergistic mechanism and exhibiting multiple inherent technical deficiencies.

[0003] Current river and lake management often suffers from a focus on water bodies while neglecting bottom sediments, or a disconnect between bottom sediment and water body management. Traditional dredging operations cause significant disturbance, making it easy for pollutants deposited in bottom sediments to be released again, leading to a short-term rebound in the treatment effect. Relying solely on aeration or the introduction of exogenous microorganisms is too limited in function and cannot sustainably prevent the migration and release of endogenous pollutants from bottom sediments into the overlying water bodies.

[0004] Existing in-situ sediment remediation technologies mainly fall into three categories: sediment passivation and covering, in-situ oxygen release regulation, and sediment microbial improvement. Sediment passivation and covering often involves spreading a single clay or iron salt modified material on the sediment surface, which can only temporarily inhibit phosphorus release and cannot simultaneously treat ammonia nitrogen and heavy metal pollutants in the sediment pore water. The passivation layer is constantly disturbed by sediment and damaged by hydraulic erosion, leading to continuous nitrogen penetration and release. Furthermore, the passivation layer lacks root space and cannot rely on aquatic plants to build a long-term microbial degradation system. In-situ oxygen release technology only unidirectionally replenishes oxygen to the sediment to enhance the activity of aerobic bacteria, lacking an adsorption and filtration structure to intercept suspended organic debris in the sediment. Pollutant degradation products cannot be fixed in situ and remain in the pore water. The flow migrates to the overlying water body; microbial modification involves directly adding microbial agents to the sediment, but these agents are easily adsorbed and lost by sediment particles and rapidly inactivated in anaerobic environments. Without a stable fixed carrier to support the long-term survival of the microbial community, the effective period of a single addition is less than 3 months, resulting in high engineering operation and maintenance costs; conventional sediment remediation ecological bags are simply filled with passivation materials and do not integrate slow-release electronic regulation media and local composite functional microbial agents, making it impossible to simultaneously achieve multi-pathway pollutant removal through adsorption, passivation, and microbial degradation. Furthermore, the bags lack a permeable and mud-blocking interface control design, making it easy for remediation agent particles to leak out and posing a significant risk of sediment disturbance and resuspension.

[0005] Existing water purification technologies include three types: ecological floating beds, algae-bacterial symbiotic filter media, and constructed wetlands. All of these are suspended or placed inside the water body and cannot interfere with the endogenous release process of the bottom sediment. Conventional ecological floating beds rely solely on the shallow root systems of emergent plants to absorb nutrients from the water. These roots only reach a depth of 0.5 to 1 meter underwater, failing to reach the surface of the sediment. The continuous release of nitrogen and phosphorus from the sediment further replenishes the water, overloading the floating bed's purification load and causing its effectiveness to rapidly decline over time. Algal-microbe symbiotic reactors only target dissolved pollutants in the water, lacking a bottom sediment seepage circulation and guidance structure. Highly polluted pore water from the sediment directly diffuses into the middle water layer, exceeding the degradation capacity of the algal-microbe system and triggering a malignant algal bloom. Ordinary artificial aquatic plant substrates have poor biocompatibility, resulting in low microbial biofilm attachment and insufficient mass transfer efficiency under static placement. They lack hydrophilic and charge-modification processes to enhance bacterial attachment and hydraulic disturbance mass transfer capabilities. Constructed wetlands require large areas of onshore land, making them unsuitable for in-situ placement in rivers and lakes. The large amount of civil engineering and high land costs make them unsuitable for narrow urban waterways, small landscape lakes, and sensitive water areas with limited dredging at estuaries.

[0006] Existing composite remediation carriers are simply superimposed with a sediment cover layer and a floating bed on the water surface, without a hydraulic circulation channel connecting the sediment and the water body. This prevents the highly polluted water from being directionally transported to the water purification unit for centralized degradation, resulting in a complete disconnect between the sediment and water purification processes. Furthermore, the lack of a vertical coupling structure between sediment remediation eco-bags and artificial aquatic plants prevents the formation of a complete and synergistic purification chain involving sediment passivation, interstitial water purification, and overlying water quality improvement. The absence of a multi-source stratified sensing system and adaptive intelligent control logic also hinders the dynamic adjustment of hydraulic circulation flow, aeration and oxygen supply rates, and slow-release electron oxygenation rates based on the sediment's internal release intensity and the real-time pollution load of the water body. Consequently, the carrier's purification capacity is significantly reduced. With a fixed force, energy consumption is severely wasted in low-pollution conditions, while purification efficiency is insufficient in high-pollution conditions. A complete multi-level purification structure has not been constructed; there is no progressively coupled degradation pathway between sediment impoundment, sediment microbial degradation, surface plant absorption, mid-layer algal oxidation, and bottom-layer flocculation filtration, resulting in a broken pollutant removal chain. Existing simple, superimposed composite carriers generally achieve total nitrogen and total phosphorus removal rates between 40% and 55%, with a long-term stable treatment cycle of less than 12 months. Existing carriers lack a standardized modular matrix layout structure, making on-site assembly difficult, underwater stability poor, and prone to displacement and damage during flood season due to water flow impacts. Repair projects require frequent maintenance, leading to high overall treatment costs.

[0007] Meanwhile, existing technologies lack quantitative coupling control algorithms to support intelligent automated operation. Relying solely on manual timed start-stop of equipment, they cannot quantitatively distinguish the risk level of endogenous release from sediment and the matching relationship with the real-time pollution load of the water body. They cannot achieve the coordinated adaptive adjustment of the oxygen release passivation rate of the sediment control unit, the hydraulic circulation of the water purification unit, and the aeration system. They cannot reduce the total amount of endogenous pollution release from the sediment source, and can only passively degrade pollutants that have spread to the water body. The treatment is only a temporary solution and cannot address the root cause. Long-term repeated treatments are unlikely to stably maintain the Class III to Class IV surface water quality standards. Conventional composite carriers lack a complete ecological safety and long-term stability assessment system, and cannot quantify the structural integrity of the bag under water flow scouring and alternating wet and dry conditions, or the functional degradation law of the repair materials. It is difficult to accurately determine the effective service life of the carrier.

[0008] In summary, existing methods for single-body sediment remediation, single-body water purification, and simple stacked composite carriers suffer from multiple shortcomings, including technological fragmentation, lack of vertically coupled synergistic remediation links, absence of an integrated biological-abiotic sediment remediation system, low mass transfer efficiency of artificial aquatic plant microbial enrichment, lack of intelligent adaptive regulation, poor long-term purification stability, incomplete blocking of endogenous pollution, low ease of engineering deployment, and lack of an ecological safety verification system. The industry urgently needs a long-term synergistic purification composite ecological carrier that can simultaneously couple endogenous sediment degradation and multi-level stratified water purification, integrates permeable sediment-blocking ecological bags, modified artificial aquatic plant vertical coupling enhancement structures, is equipped with multi-source sensing intelligent coupling regulation algorithms, modular and splicable deployment, and a complete ecological safety and performance verification system. Summary of the Invention

[0009] The purpose of this invention is to provide a composite ecological carrier for the synergistic treatment of endogenous pollution in river and lake bottom sediments and water purification, so as to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A composite ecological carrier for the synergistic treatment of endogenous pollution in river and lake bottom sediments and water purification.

[0012] Furthermore, the in-situ sediment regulation matrix unit includes a multi-layer composite slow-release oxygen barrier layer, a benthic microbial fixation framework, a root penetration and colonization cavity, and a sediment seepage channel. The multi-layer composite slow-release oxygen barrier layer is laid flat and adheres to the surface of the river and lake sediment. The benthic microbial fixation framework is integrally formed inside the multi-layer composite slow-release oxygen barrier layer. The root penetration and colonization cavity vertically penetrates the upper and lower surfaces of the multi-layer composite slow-release oxygen barrier layer. The sediment seepage channel is opened laterally in the lower layer of the multi-layer composite slow-release oxygen barrier layer. One end of the sediment seepage channel is connected to the fluid pipeline at the bottom of the water stratified purification unit, and the other end is connected to the bottom layer of the benthic microbial fixation framework.

[0013] Furthermore, the multi-layer composite slow-release oxygen barrier layer consists of a surface adsorption and filtration layer, a middle slow-release oxygen reaction layer, and a bottom passivation barrier layer arranged sequentially from top to bottom. The thickness of the surface adsorption and filtration layer ranges from 3 cm to 8 cm, the thickness of the middle slow-release oxygen reaction layer ranges from 10 cm to 20 cm, and the thickness of the bottom passivation barrier layer ranges from 5 cm to 12 cm. The surface adsorption and filtration layer is filled with modified biochar composite zeolite particles, the middle slow-release oxygen reaction layer is loaded with calcium peroxide slow-release oxygen ions and denitrifying functional bacteria, and the bottom passivation barrier layer is a modified clay composite iron-aluminum oxide passivation material. The three-layer structure is fixed into an integrated flat plate structure by stitching together a biodegradable plant fiber mesh.

[0014] Furthermore, the water stratification purification unit includes a surface floating plant symbiosis module, a middle layer algae and bacteria reaction module, a bottom layer suspended flocculation filtration module, and a circulating hydraulic drive component. The surface floating plant symbiosis module is located at the surface of the water body. The middle layer algae and bacteria reaction module is suspended by flexible cables in a water depth range of 1 to 2.5 meters below the surface floating plant symbiosis module. The bottom layer suspended flocculation filtration module is connected to the bottom of the middle layer algae and bacteria reaction module through rigid support columns. The circulating hydraulic drive component has a built-in water pump pipeline. The inlet of the circulating hydraulic drive component is connected to the bottom sediment seepage guide channel. The outlet of the circulating hydraulic drive component is diverted to connect the middle layer algae and bacteria reaction module and the bottom layer suspended flocculation filtration module.

[0015] Furthermore, the surface floating plant symbiosis module has an array of planting tanks, which are filled with slow-release nutrient fillers and planted with aerated emergent plants. A three-dimensional elastic bio-based carrier is suspended on the lower surface of the surface floating plant symbiosis module, and a composite biofilm of polyphosphate-accumulating bacteria and photosynthetic bacteria is attached to the surface of the three-dimensional elastic bio-based carrier. The middle layer algae reaction module is sealed with a light-transmitting closed cavity, and a mixed algal solution of Chlorella and Scenedesmus is placed inside the cavity. Adjustable nano-aeration discs are arranged on the side wall of the cavity, and the nano-aeration discs are connected to the built-in air pump of the circulating water drive component through air pipes. The bottom layer suspended flocculation filtration module is filled with porous volcanic rock modified filter media, and modified chitosan slow-release flocculants are pre-embedded inside the filter media.

[0016] Furthermore, the multi-source sensing and collaborative control unit includes a bottom sediment in-situ sensing array, a water stratification sensing group, an edge computing controller, and an adaptive flow distribution actuator. The bottom sediment in-situ sensing array is pre-embedded inside each layer of the multi-layer composite slow-release oxygen barrier layer. The water stratification sensing group is fixed at the corresponding water depth positions of the surface floating plant symbiosis module, the middle layer bacteria and algae reaction module, and the bottom layer suspended flocculation filtration module. The bottom sediment in-situ sensing array and the water stratification sensing group are all unidirectionally connected to the signal input terminal of the edge computing controller through wired transmission lines. The control output terminal of the edge computing controller is electrically connected to the adaptive flow distribution actuator, which is connected in series in the middle section of the circulating hydraulic drive component pipeline.

[0017] Furthermore, the sediment in-situ sensing array includes a redox potential detection probe, a sediment total phosphorus in-situ sensor, a sediment ammonia nitrogen concentration probe, and a sediment pore water velocity collector; the water stratification sensing group includes a water dissolved oxygen sensor, a water total nitrogen online monitoring probe, a water turbidity acquisition module, and a water light intensity detector; the edge computing controller has a built-in endogenous pollution collaborative coupling control algorithm, which outputs three types of control commands based on real-time sensor data: hydraulic circulation flow rate, aeration duration, and slow-release oxygen release rate; the adaptive flow distribution actuator receives the control commands and completes the stepless adjustment of pipeline on / off and fluid flow.

[0018] Furthermore, the synergistic coupling control algorithm for endogenous pollution includes a sediment endogenous release risk classification model, a water body purification load matching calculation function, and a carrier adaptive control output formula. The sediment endogenous release risk classification model is expressed as R=α×C_P+β×C_N-γ×DO_S+δ×V_P, where R represents the sediment endogenous pollution release risk index, C_P represents the real-time detected concentration of total phosphorus in sediment pore water, C_N represents the real-time detected concentration of ammonia nitrogen in sediment pore water, DO_S represents the dissolved oxygen equivalent value converted from in-situ redox potential in sediment, V_P represents the average seepage velocity of sediment pore water, and α, β, γ, and δ are fixed weight coefficients of the model. The water body purification load matching calculation function is expressed as L=k1×TN_W+k2×TP_W+k3×TUR_W, where L... The values ​​represent the real-time pollution load of the water body, TN_W represents the total nitrogen concentration, TP_W represents the total phosphorus concentration, TUR_W represents the turbidity value, and k1, k2, and k3 are water load conversion coefficients. The adaptive control output formula of the carrier includes the hydraulic circulation flow output Q=Q0×(R / L)^η, the aeration duration output T=T0×√(R / DO_W), and the slow-release oxygen release rate output V_O=V_O0×exp(R×σ). Q represents the real-time pipeline circulation flow, Q0 is the baseline circulation flow, η is the flow regulation index, T represents the cumulative aeration time per day, T0 is the baseline aeration time, DO_W represents the dissolved oxygen concentration in the middle layer of water, V_O represents the oxygen release rate of the slow-release oxygen carrier in the middle layer, V_O0 is the baseline oxygen release rate, and σ is the oxygen release regulation coefficient.

[0019] Furthermore, the raw materials for preparing modified biochar composite zeolite particles include straw biochar, clinoptilolite, and nano-iron oxides, with a mass ratio of 55-65:25-35:5-10; the calcium peroxide slow-release oxygen body is made by pressing calcium peroxide powder, sodium alginate binder, and coconut shell fiber filler, with a mass ratio of 40-50:30-40:15-25; the raw materials for modified clay composite iron-aluminum oxide passivation materials include bentonite, polyferric sulfate, and aluminum hydroxide gel, with a mass ratio of 60-70:20-28:2-8; the raw material for the three-dimensional elastic bio-based carrier is modified polyethylene elastic filament mixed with coconut fiber; and the modified chitosan slow-release flocculant microspheres are made by rolling chitosan, citric acid, and diatomaceous earth into spheres, with a mass ratio of 35-45:10-18:40-50.

[0020] Furthermore, the carrier adopts a matrix-style modular deployment scheme. The planar dimensions of a single composite ecological carrier unit are 2 meters × 3 meters. Adjacent units are spliced ​​together by snap-fit ​​biodegradable connecting strips. Concrete counterweight anchor blocks are set at the bottom of the bottom sediment in-situ regulation matrix unit. The counterweight anchor blocks are bound to the four corners of the multi-layer composite slow-release oxygen blocking layer by nylon ropes. Buoyancy adjustment floats are arranged at the edges of the surface floating plant symbiosis module. The buoyancy adjustment floats are filled with hollow plastic floats that can increase or decrease buoyancy. After the entire carrier is deployed, the bottom sediment in-situ regulation matrix unit completely fits the surface of the river and lake bottom sediment without any suspended space gaps. The water body stratification purification module is vertically distributed in the range from the water surface to a depth of 3 meters underwater. The multi-source sensing and collaborative regulation unit is centrally arranged inside the shore control cabinet. The shore control cabinet is connected to all underwater sensing and execution components for power supply through waterproof cables.

[0021] The composite ecological carrier for the synergistic treatment of endogenous pollution in rivers and lakes—combining sediment and water purification—of the present invention has the following beneficial effects compared with existing technologies:

[0022] This carrier can integrate mineral physical adsorption, encapsulated zero-valent iron non-biological passivation, and local functional bacteria microbial degradation to form a complete biological-non-biological synergistic remediation system from the source of sediment, relying on permeable mud-blocking ecological bags, and bidirectionally inhibit the endogenous release of organic matter, nitrogen, phosphorus and heavy metals in the sediment.

[0023] The eco-bag adopts a gradient pore size fabric structure, which, while ensuring the free exchange of water and oxygen, inhibits the disturbance and resuspension of bottom sediment and prevents the leakage of remediation agent particles inside the bag. Through the vertical coupling of the eco-bag and modified artificial aquatic plants with bottom sediment seepage diversion channels, the pore water of highly polluted bottom sediment is directionally transported to the vertical stratified water purification unit for step-by-step degradation.

[0024] Artificial aquatic plants are modified with hydrophilicity, charge, and plasma to achieve high-density microbial biofilm formation. Water flow and swaying enhance the efficiency of water mass transfer and reoxygenation, constructing a complete and synergistic remediation chain of bottom sediment passivation, interstitial water purification, and overlying water quality improvement, which significantly improves the removal effect of total nitrogen, total phosphorus, and heavy metals in the water.

[0025] Equipped with a full-domain hierarchical sensing and quantitative coupling control algorithm, it can adaptively adjust the operating parameters of hydraulic, aeration, and slow-release electronic oxygenation equipment according to the real-time endogenous risk of bottom sediment and the pollution load of water body. It can also simultaneously match the ecological bag deployment density and artificial aquatic plant arrangement spacing to optimize the purification load, effectively reducing operation and maintenance energy consumption and manual inspection workload. The multi-layer composite matrix, strip ecological bags, and modified artificial aquatic plant microbial community have strong adhesion stability. The entire set of equipment can be deployed once and the long-term operation cycle can reach 36 months, which greatly reduces the cost of repeated construction.

[0026] Standardized modular assembly, combined with counterweight anchor blocks and adjustable buoyancy floats, is suitable for various bottom sediments such as silt, sand, and clay, as well as water depths of 0.8 to 3 meters in rivers, lakes, reservoirs, and estuaries where dredging is restricted and sensitive. It can be deployed in situ without large-scale dredging and with minimal disturbance to the construction environment. It relies on a symbiotic ecological chain of bacteria, algae, and plants to degrade pollutants, eliminating the need for continuous addition of chemical agents and the risk of secondary pollution.

[0027] It is equipped with indoor simulation, on-site enclosure performance verification and complete ecological safety assessment process, which can quantify the efficiency of sediment pollutant reduction and the improvement of water indicators, clarify the long-term water flow erosion and the decline of the structure and function of the sediment, and can maintain the excellent water quality of rivers and lakes in a long-term stable manner; it has outstanding ecological, social and economic benefits, and is suitable for various engineering scenarios such as watershed comprehensive management, wetland ecological restoration and long-term operation and maintenance of black and odorous water bodies. Attached Figure Description

[0028] Figure 1 This is a block diagram showing the signal and fluid connectivity logic of a multi-source sensing and collaborative control unit.

[0029] Figure 2 This is a flowchart of the data transmission and computation logic of the endogenous pollution synergistic coupling regulation algorithm. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] like Figure 1 and Figure 2 As shown:

[0032] Example 1: Complete Preparation and Deployment Scheme for Remediation Carriers for Endogenous Pollution in Urban Black and Odorous Shallow Rivers

[0033] The target of the restoration is a black and odorous river in the urban area, 8 meters wide and 1.5 meters deep on average, with a bottom sediment thickness of 0.6 meters. The ammonia nitrogen concentration in the bottom sediment pore water is 4.2 mg / L, the total phosphorus concentration is 0.78 mg / L, and the cumulative levels of heavy metals lead and cadmium exceed the standards. The water body is mildly black and odorous due to the release of endogenous substances from the bottom sediment over the years, and blue-green algae blooms occur in summer. The area is under strict dredging control, and only low-disturbance in-situ restoration processes are permitted.

[0034] Step 1: Preparation of raw materials for each functional filler

[0035] Surface adsorption and filtration layer modified mineral composite particles: 60 parts by weight of straw biochar, 30 parts by weight of clinoptilolite, and 10 parts by weight of nano iron oxide are crushed, mixed evenly, and granulated to a particle size of 3 mm to 6 mm. They are then dried at 105 degrees Celsius for 2 hours for later use.

[0036] Mid-layer slow-release electron-emitting matrix: 45 parts by weight of coated zero-valent iron powder, 35 parts by weight of sodium alginate binder, and 20 parts by weight of coconut shell fiber filler are mixed with water to form a paste, pressed into a 1.5 cm thick sheet matrix, and air-dried for 24 hours. The matrix is ​​then sprayed with a local compound bacterial solution containing denitrifying Bacillus, denitrifying Pseudomonas, polyphosphate Pseudomonas, and heavy metal tolerant bacteria, with a viable bacterial concentration of not less than 10^8 colony-forming units per milliliter.

[0037] The bottom passivation barrier layer modified clay composite iron-aluminum oxide passivation material consists of 65 parts by weight of bentonite, 27 parts by weight of polyferric sulfate, and 8 parts by weight of aluminum hydroxide gel. Water is added and mixed evenly, and the mixture is pressed into a passivation plate with a thickness of 8 cm for later use.

[0038] Modified chitosan slow-release flocculation beads for bottom-layer suspended flocculation filtration module: 40 parts by weight of chitosan, 15 parts by weight of citric acid, and 45 parts by weight of diatomaceous earth are rolled into spherical particles with a diameter of 5 mm, dried at low temperature and sealed for storage.

[0039] Three-dimensional elastic bio-based carrier: 65 parts by weight of modified polyethylene elastic yarn are mixed with 35 parts by weight of coconut fiber and woven into a three-dimensional mesh carrier with a pore size of 1 cm. The carrier is pre-coated by soaking in a compound bacterial solution of photosynthetic bacteria and polyphosphate bacteria for 2 hours.

[0040] Preparation of modified artificial aquatic plant ribbons: Carbon fiber felt substrate is selected, and after plasma cleaning, a hydrophilic and conductive coating is sprayed to complete charge modification. The ribbons are immersed in local water to enrich and degrade bacterial solution for 72 hours to complete directional biofilm formation. Each ribbon is 2 meters long and 10 centimeters wide.

[0041] Water-permeable and mud-blocking strip-shaped ecological bags are sewn together: using gradient pore size polyester ecological textile fabric, the bags are sewn into strips with a length of 2 meters, with a pre-reserved top filling opening, and biodegradable jute thread is used for the stitching.

[0042] Step 2: In-situ substrate regulation and integrated molding of matrix units

[0043] The three-layer composite slow-release electron oxygen release barrier layer is laid from top to bottom as follows: a 5 cm thick surface adsorption and filtration layer, a 15 cm thick middle slow-release electron oxygen release reaction layer, and an 8 cm thick bottom passivation barrier layer. The three layers are then wrapped and sewn together with a biodegradable jute fiber net. The overall dimensions are 2 m × 3 m for a single-unit flat plate. Vertically, 8 cm diameter root penetration and planting cavities are created, with a horizontal spacing of 30 cm and a vertical spacing of 40 cm. At the bottom layer, horizontally, 5 cm diameter sediment seepage channels are created, with a channel spacing of 50 cm. Pipe joints are pre-installed at the ends of the channels for... The water inlet pipe of the circulating water drive component is connected; the benthic microbial fixation skeleton is made of coconut shell porous fiberboard embedded in the middle slow-release electron oxygen release reaction layer, with a skeleton pore diameter of 1 cm, which is used to fix functional bacteria and prevent loss; the three-layer composite matrix is ​​filled into the strip-shaped ecological bag as a whole, and the filling density inside the bag is controlled at 0.8 t / m³, and the filling port is sealed to complete the bag sealing; nylon ropes are tied to the four corners of the unit, and the ends of the ropes are connected to concrete counterweight anchor blocks weighing 15 kg; modified artificial aquatic plant ribbons are evenly tied to the upper surface of the ecological bag, with the ribbons laid at intervals of 0.5 meters.

[0044] Step 3: Assemble the water stratification purification unit

[0045] Surface floating plant symbiosis module: 2m×3m polypropylene floating board, with evenly spaced 12cm diameter array planting trenches, the planting trenches are filled with slow-release nutrient filler, and planted with a mixture of emergent plants with aeration tissue such as Vallisneria natans, Acorus calamus and Canna indica; three-dimensional elastic bio-based carriers are evenly suspended on the lower surface of the floating board, with a suspension length of 1.2m; four buoyancy adjustment buoys are installed on the four sides of the floating board, and hollow plastic buoys are placed inside the buoys. The draft of the floating board is adjusted by adding or removing buoys according to the water depth of the river.

[0046] Mid-layer algae reaction module: A light-transmitting, sealed organic glass chamber, 2 meters long, 1 meter wide, and 0.8 meters high, suspended 1.8 meters below the float by four flexible nylon cables; the chamber is filled with a mixed algal solution of Chlorella and Scenedesmus, maintaining a chlorophyll concentration of 20 to 35 micrograms per liter; six adjustable nano-aeration discs are arranged on the left and right side walls of the chamber, and the air pipes of the aeration discs are connected upward to the built-in air pump above the float.

[0047] Bottom layer suspended flocculation filter module: Rigid polypropylene support columns are connected to the bottom of the middle layer cavity, with a column height of 0.7 meters; the filter module shell has water-permeable holes, and the inside is filled with porous volcanic rock filter media with a particle size of 1 to 3 cm. The filter media is uniformly mixed with modified chitosan slow-release flocculation balls, and the filling volume of the balls accounts for 15% of the total volume of the filter media.

[0048] Circulating hydraulic drive components: Built-in adjustable flow water pump, diversion pipeline, air pump, the water inlet pipe extends upward to connect to the end connector of the bottom sediment seepage guide channel, and the water outlet pipe is divided into two paths, one of which connects to the bottom of the middle layer of bacteria and algae reaction chamber, and the other of which enters the bottom layer of suspended flocculation filter module, so as to realize the stratified transportation and purification of bottom sediment seepage water.

[0049] Step 4: Installation and commissioning of the multi-source sensing and coordinated control unit

[0050] Pre-embedded in-situ bottom sediment sensing array: Oxidation-reduction potential detection probe, total phosphorus in-situ sensor in sediment, ammonia nitrogen concentration probe in sediment, pore water flow velocity collector in sediment, and heavy metal detection sensor in sediment are pre-embedded in the surface adsorption and filtration layer, the middle slow-release electron oxygen release reaction layer, and the bottom passivation barrier layer of the ecological bag. Two sets of sensing probes are deployed in each layer, and all sensing cables are brought together and led upward to the water surface along the flow channel pipeline.

[0051] The water stratification sensing group is fixed as follows: a water light intensity detector and a water turbidity acquisition module are fixed on the lower surface of the surface floating plate; a dissolved oxygen sensor, a total nitrogen online monitoring probe, and a total phosphorus detection module are installed inside the middle layer algae and bacteria cavity; a water turbidity verification acquisition module is added to the bottom filtration module; a water quality micro sensor is added to the middle section of the modified artificial aquatic plant ribbon; and all water sensing cables are uniformly connected to the shore control cabinet.

[0052] The edge computing controller is integrated with the adaptive flow distribution actuator: The edge computing controller has a built-in storage module and computing chip, pre-programmed with a complete internal pollution collaborative coupling control algorithm. All sensor signals are connected to the controller's signal input terminal via waterproof wired lines. The adaptive flow distribution actuator is an electric proportional regulating valve, connected in series in the middle section of the main pipeline of the circulating water drive component. The controller outputs a control signal electrically connected to the regulating valve drive module, enabling stepless adjustment of the pipeline flow rate from 0 to 2.5 cubic meters per hour. The shore-based control cabinet has a built-in 220-volt waterproof power supply module, continuously powering all underwater sensors, water pumps, and air pumps.

[0053] Step 5: Modular deployment and performance / ecological safety verification of the river channel on site

[0054] Eight sets of composite ecological carrier units of this invention are continuously deployed along the river's flow direction. Adjacent units are fixed together by snap-fit ​​jute connecting strips on their sides. The seepage channels and aeration pipes of adjacent units are connected by waterproof quick-connect joints. The packaged strip-shaped ecological bag bottom units are laid flat on the surface of the riverbed sediment using a laying boat. Four corner concrete counterweights are lowered into the sediment to ensure the bags fit completely without any gaps. The modified artificial aquatic plant ribbons naturally extend upwards and float in the water. The surface floating plant symbiosis module is hoisted and placed on the water surface. Flexible slings and support columns are connected to complete the vertical positioning of the middle and bottom purification modules. The seepage channels of the sediment are connected to the water inlet pipe of the circulating hydraulic drive component. The underwater joints are sealed with waterproof sealant. All underwater sensor cables are connected to the control cabinet on the shore. The circuit and algorithm parameters are calibrated and debugged, and the equipment is started to enter the adaptive automatic operation mode.

[0055] After deployment, a field-enclosed test area was established for 6 months of continuous performance verification. A blank control area was simultaneously set up to eliminate the influence of hydraulic dilution and natural decay. The pollutant reduction rate contributed by the carrier was ≥90%. Simultaneously, benthic organism toxicity tests were conducted to assess ecological safety, and the structural integrity of the ecological bag under water flow erosion was continuously recorded. After 12 months of continuous and stable operation of the carrier, on-site sampling and testing showed: the ammonia nitrogen concentration in the sediment pore water decreased to 0.68 mg / L, a reduction rate of 83.8%; the total phosphorus concentration in the sediment pore water decreased to 0.11 mg / L, a reduction rate of 85.9%; the sediment organic matter removal rate was 76%; and the sediment lead and cadmium heavy metal fixation efficiency exceeded 80%. The river water... The average total nitrogen concentration was 1.02 mg / L and the average total phosphorus concentration was 0.09 mg / L, consistently meeting the Class IV surface water quality standard. The daily average water and electricity consumption of the equipment was reduced by 38% compared to traditional fixed-operation ecological floating beds. The overall structure of the carrier was undamaged, with no leakage of remediation agents or large-scale resuspension of bottom sediment in the strip-shaped ecological bags. The slow-release electron oxygen-releasing gas in the middle layer still had stable passivation and oxygen release capabilities. The activity of the artificial aquatic plant biofilm bacteria was normal, with no large-scale loss of bacteria or packing compaction issues. Long-term observation confirmed that the entire carrier had no significant toxic effects on benthic organisms. The bag structure remained intact after 12 months of continuous water flow scouring, and the effective service life was estimated to be up to 36 months based on the functional decay law.

[0056] Example 2: Adaptation and Adjustment Scheme for Remediation Carriers of Intrinsic Pollution in Small Shallow Lakes

[0057] Target of restoration: A small urban landscape lake with a water area of ​​5200 square meters and an average depth of 2.2 meters. The bottom sediment is mainly composed of silty clay, and seasonal cyanobacterial blooms are frequent. The release of endogenous phosphorus and heavy metals from the bottom sediment is the core pollution cause. This is a landscape-sensitive water area, and large-scale dredging is prohibited. Adjusted parameters: The spacing between single-unit composite carriers is increased to 4 meters; the thickness of the bottom passivation barrier layer is adjusted to 10 cm; the thickness of the middle slow-release electron oxygen release reaction layer is adjusted to 18 cm; the filling density of the strip-shaped ecological bags is adjusted to 0.9 t / m³; the length of the modified artificial aquatic plant ribbons is increased to 2.8 meters, and the spacing between them is 0.6 meters; the number of buoys inside the buoyancy regulating floats is increased to adapt to a water depth of 2.2 meters; the algorithmic baseline aeration time T0 is adjusted to 10 hours, and the baseline circulation flow rate Q0 is adjusted to 3 cubic meters per hour. At that time, each unit of the bottom sediment in-situ sensing array was equipped with one additional set of bottom sediment heavy metal in-situ detection sensors; a total of 22 modular units were deployed, and the matrix was evenly distributed across the bottom of the lake; after deployment, indoor simulation tests were conducted in advance to predict the pollutant reduction effect; the carrier operated continuously for 24 months, and there was no cyanobacterial bloom in the water body throughout the year; the total phosphorus release reduction rate in the bottom sediment reached 90.2%; the total phosphorus in the water body was stably below 0.1 mg / L; there were no adverse changes in the benthic biological community structure; the ecological bags were not damaged or leaked; and the long-term operation stability was good.

[0058] Complete algorithm operation example

[0059] Taking the real-time acquisition of sensor data from the river channel in Example 1 as an example, this paper fully demonstrates all calculation steps of the synergistic coupling control algorithm for endogenous pollution, and discloses all original acquired data, intermediate calculated values, and final control output parameters. The maximum oxygen release rate threshold of the material is set to V_Omax = 800 mg / m² / day.

[0060] Real-time sensor acquisition of raw data:

[0061] C_P=0.78mg / L, C_N=4.2mg / L, DO_S=1.1mg / L, V_P=3.2cm / h;

[0062] TN_W=2.8mg / L, TP_W=0.32mg / L, TUR_W=42NTU, DO_W=2.3mg / L.

[0063] Calculate the risk index R of endogenous release from sediment:

[0064] R=12.6×0.78+9.8×4.2-7.2×1.1+4.5×3.2

[0065] R=9.828+41.16-7.92+14.4=57.468

[0066] Calculate the comprehensive pollution load index L of the water body:

[0067] L=6.2×2.8+18.5×0.32+0.35×42

[0068] L = 17.36 + 5.92 + 14.7 = 37.98

[0069] Real-time hydraulic circulation flow rate Q is calculated (Q0=2.5, η=0.65):

[0070] Q = 2.5 × (57.468 / 37.98)^0.65

[0071] Q≈3.27 cubic meters per hour, the adaptive regulating valve automatically adjusts to this flow rate to match the seepage of the ecological bag and the mass transfer load of the artificial aquatic plants.

[0072] Calculation of daily cumulative aeration time T (T0=8):

[0073] T = min (8 × √(57.468 / 2.3), 24)

[0074] The theoretical calculation value is approximately 40 hours, exceeding the physical limit of 24 hours per day. Therefore, T = 24 hours is adopted. The controller operates in a full-load intermittent mode for 24 hours per day, alternating between start and stop in 6 cycles to balance reoxygenation effect and equipment lifespan.

[0075] Calculation of the sustained-release electron oxygen release rate V_O (V_O0=120, σ=0.028):

[0076] V_O=min (120×exp (57.468×0.028),800)

[0077] The theoretically calculated value is approximately 600 mg / m² / day, which does not exceed the maximum threshold; therefore, it is implemented at 600 mg / m² / day. The mid-layer slow-release electron-derived oxygen gas release rate is adjusted to match this release rate through bag pore opening, enhancing the passivation of heavy metals and the degradation of nitrogen and phosphorus in the sediment.

[0078] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0079] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A composite ecological carrier for the synergistic treatment of endogenous pollution in river and lake sediments and water purification, characterized in that, It comprises a bottom sediment in-situ regulation matrix unit, a water stratification and purification unit, and a multi-source sensing and synergistic regulation unit. The bottom sediment in-situ regulation matrix unit is deployed on the surface of river and lake bottom sediments, while the water stratification and purification unit is suspended inside the overlying water. The multi-source sensing and synergistic regulation unit establishes signal and fluid communication relationships with the bottom sediment in-situ regulation matrix unit and the water stratification and purification unit, respectively. The three work together to block the release of endogenous organic matter, nitrogen, phosphorus, and heavy metals from the bottom sediment and to degrade pollutants in the water at multiple levels, achieving a fully coupled purification process. The bottom sediment in-situ regulation matrix unit uses permeable mud-blocking strip-shaped ecological bags to carry composite bottom sediment remediation agents, while the water stratification and purification unit integrates modified artificial aquatic plants to achieve microbial enrichment and mass transfer. The bottom sediment in-situ regulation matrix unit and the water stratification and purification unit are vertically coupled to form a synergistic remediation link of bottom sediment passivation, interstitial water purification, and overlying water quality improvement.

2. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 1, is characterized in that, The in-situ sediment regulation matrix unit comprises a multi-layered composite slow-release electronic oxygen release barrier layer, a benthic microbial fixation framework, a root penetration and planting cavity, a sediment seepage channel, and a permeable sediment-blocking strip-shaped ecological bag. The multi-layered composite slow-release electronic oxygen release barrier layer is laid flat against the surface of the river and lake sediment and is encapsulated inside the permeable sediment-blocking strip-shaped ecological bag. The benthic microbial fixation framework is integrally formed inside the multi-layered composite slow-release electronic oxygen release barrier layer. The root system penetrates the planting cavity vertically through the upper and lower surfaces of the multi-layered composite slow-release electronic oxygen release barrier layer. The sediment seepage channel is opened horizontally in the lower layer of the multi-layered composite slow-release electronic oxygen release barrier layer. One end of the sediment seepage channel is connected to the fluid pipeline at the bottom of the water stratified purification unit, and the other end is connected to the bottom layer of the benthic microbial fixation framework. The permeable sediment-blocking strip-shaped ecological bag, through the fabric pore size design and surface hydrophilicity / hydrophobicity regulation, enables free exchange of water and dissolved oxygen, while preventing the leakage of remediation agent particles inside the bag and inhibiting sediment resuspension.

3. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 2, is characterized in that, The multi-layered composite slow-release electron oxygen release barrier layer consists of a surface adsorption and filtration layer, a middle slow-release electron oxygen release reaction layer, and a bottom passivation barrier layer, arranged sequentially from top to bottom. The thickness of the surface adsorption and filtration layer ranges from 3 cm to 8 cm, the thickness of the middle slow-release electron oxygen release reaction layer ranges from 10 cm to 20 cm, and the thickness of the bottom passivation barrier layer ranges from 5 cm to 12 cm. The surface adsorption and filtration layer is filled with modified mineral composite particles, the middle slow-release electron oxygen release reaction layer is loaded with a zero-valent iron slow-release electron matrix and native functional microbial communities, and the bottom passivation barrier layer is a modified clay composite iron-aluminum oxide passivation material. The three-layer structure is fixed into an integrated flat plate by sewing together a biodegradable plant fiber mesh and filled into a strip-shaped ecological bag. The composite sediment remediation agent integrates the physical adsorption mineral carrier, the slow-release electron non-biological passivation material, and the native functional microbial agent to form a biological-non-biological synergistic remediation system, which simultaneously completes the adsorption, degradation, and passivation of sediment organic matter, nitrogen, phosphorus, and heavy metals.

4. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 2, is characterized in that, The water stratification unit comprises a surface floating plant symbiosis module, a middle layer algae and bacteria reaction module, a bottom layer suspended flocculation filtration module, a circulating hydraulic drive component, and a modified artificial aquatic plant purification ribbon. The surface floating plant symbiosis module is positioned at the surface of the water body. The middle layer algae and bacteria reaction module is suspended by flexible cables in a water depth range of 1 to 2.5 meters below the surface floating plant symbiosis module. The bottom layer suspended flocculation filtration module is connected to the bottom of the middle layer algae and bacteria reaction module by rigid support columns. The circulating hydraulic drive component has a built-in water pump and diversion pipeline. The inlet of the circulating hydraulic drive component is connected to the bottom sediment seepage guide channel, and the outlet of the circulating hydraulic drive component is diverted to connect the middle layer algae and bacteria reaction module and the bottom layer suspended flocculation filtration module. The bottom end of the modified artificial aquatic plant purification ribbon is fixed to the upper surface of the permeable mud-blocking strip-shaped ecological bag, and the upper part extends upward and is suspended inside the water stratification unit to achieve vertical coupling.

5. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 4, is characterized in that, The surface floating plant symbiosis module features an array of planting tanks filled with slow-release nutrient fillers and planted with aerated emergent plants. A three-dimensional elastic bio-based carrier is suspended on the lower surface of the module, with a composite biofilm of polyphosphate-accumulating bacteria and photosynthetic bacteria attached to its surface. The middle layer algae-bacteria reaction module has a sealed, light-transmitting cavity containing a mixed algal solution of Chlorella and Scenedesmus. Adjustable nano-aeration discs are installed on the side walls of the cavity, connected to a built-in air pump in a circulating hydraulic drive component via air pipes. The bottom layer suspended flocculation filtration module is filled with porous volcanic rock modified filter media, with modified chitosan slow-release flocculation beads pre-embedded within. Modified artificial aquatic plants utilize high-specific-surface-area modified polyester fiber or carbon fiber felt substrates, undergoing hydrophilic coating, charge modification, and plasma treatment to enhance biocompatibility. Highly efficient degradative strains adapted to local water bodies are selected for targeted enrichment, forming a dense and stable biofilm on the surface. Under water flow, the ribbons oscillate flexibly, enhancing oxygen exchange and pollutant mass transfer efficiency.

6. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 1, is characterized in that, The multi-source sensing and collaborative control unit includes a bottom sediment in-situ sensing array, a water stratification sensing group, an edge computing controller, and an adaptive flow distribution actuator. The bottom sediment in-situ sensing array is pre-embedded inside each layer of the multi-layer composite slow-release electronic oxygen release barrier layer encapsulated in strip-shaped ecological bags. The water stratification sensing group is fixed at the corresponding water depth positions of the surface floating plant symbiosis module, the middle layer bacteria and algae reaction module, the bottom layer suspended flocculation filtration module, and the modified artificial aquatic plant ribbon. The bottom sediment in-situ sensing array and the water stratification sensing group are all unidirectionally connected to the signal input terminal of the edge computing controller through wired transmission lines. The control output terminal of the edge computing controller is electrically connected to the adaptive flow distribution actuator, which is connected in series in the middle section of the circulating hydraulic drive component pipeline.

7. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 6, is characterized in that, The in-situ sediment sensing array includes an oxidation-reduction potential detection probe, an in-situ total phosphorus sensor, a sediment ammonia nitrogen concentration probe, a sediment pore water flow velocity collector, and a sediment heavy metal detection sensor. The water stratification sensing group includes a dissolved oxygen sensor, an online total nitrogen monitoring probe, a total phosphorus detection module, a turbidity acquisition module, and a light intensity detector. The edge computing controller incorporates an endogenous pollution collaborative coupling control algorithm, which outputs three types of control commands based on real-time sensor data: hydraulic circulation flow rate, aeration duration, and slow-release electron oxygen release rate. The adaptive flow distribution actuator receives the control commands and performs stepless adjustment of pipeline on / off and fluid flow. The sensor data synchronously provides feedback on the reduction of organic matter in sediment, fixation of heavy metals, and improvement of COD and ammonia nitrogen in the water, and optimizes the carrier operation parameters by matching the density of ecological bags and the spacing of artificial aquatic plants.

8. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 7, is characterized in that, The synergistic coupling control algorithm for endogenous pollution includes a sediment endogenous release risk classification model, a water body purification load matching calculation function, and a carrier adaptive control output formula. The sediment endogenous release risk classification model is expressed as R = α × C_P + β × C_N - γ × DO_S + δ × V_P, where R represents the sediment endogenous pollution release risk index, C_P represents the real-time detected total phosphorus concentration in sediment pore water, C_N represents the real-time detected ammonia nitrogen concentration in sediment pore water, DO_S represents the dissolved oxygen equivalent value converted from in-situ redox potential in sediment, V_P represents the average seepage velocity in sediment pore water, and α, β, γ, and δ are fixed weight coefficients in the model. The water body purification load matching calculation function is expressed as L = k1 × TN_W + k2 × TP_W + k3 × TUR_W, where L represents the dimensionless comprehensive water pollution load index, TN_W represents the total nitrogen concentration in the middle layer of water, TP_W represents the total phosphorus concentration in the middle layer of water, and TUR_W... The values ​​represent the turbidity of the water body, and k1, k2, and k3 are the normalized conversion factors for water body load with dimensions. The adaptive control output formula for the carrier includes the hydraulic circulation flow rate output Q=Q0×(R / L)^η, the aeration duration output T=min (T0×√(R / DO_W),24), and the slow-release electron oxygen release rate output V_O=min (V_O0×exp (R×σ),V_Omax). Q represents the real-time pipeline circulation flow rate, Q0 is the baseline circulation flow rate, η is the flow rate adjustment index, T represents the cumulative aeration duration per day (unit: hours / day, upper limit is 24 hours), T0 is the baseline aeration duration, DO_W represents the dissolved oxygen concentration in the middle layer of water, V_O represents the slow-release electron oxygen release rate in the middle layer, V_O0 is the baseline release rate, σ is the adjustment coefficient, and V_Omax is the maximum oxygen release rate threshold of the material, determined by material performance tests. The algorithm simultaneously incorporates the degradation load of artificial aquatic plant biofilm and the functional decay cycle correction and control parameters of the ecological bag repair agent.

9. The composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in claim 1, is characterized in that, The surface adsorption and filtration layer, made of modified mineral composite particles, comprises straw biochar, clinoptilolite, and nano-iron oxides, with a mass ratio of 55-65:25-35:5-10. The middle layer, a coated zero-valent iron slow-release electron matrix, is composed of coated zero-valent iron powder, sodium alginate binder, and coconut shell fiber filler, with a mass ratio of 40-50:30-40:15-25. The bottom passivation barrier layer, made of modified clay composite iron-aluminum oxide passivation material, comprises bentonite, polyferric sulfate, and aluminum hydroxide gel, with a mass ratio of 55-65:25-35:5-10. The mass ratio range is 60-70: 20-28: 2-8; the raw material of the three-dimensional elastic bio-based carrier is modified polyethylene elastic yarn mixed with coconut fiber; the modified chitosan slow-release flocculant balls are made by rolling chitosan, citric acid, and diatomaceous earth into balls, and the mass ratio range of the three is 35-45: 10-18: 40-50; the strip-shaped ecological bags are sewn with gradient pore size ecological textile materials, the length of a single bag is 2 to 3 meters, the filling density inside the bag is controlled at 0.7~0.9 t / m³, and the spacing between adjacent modified artificial aquatic plant ribbons is 0.4 to 0.6 meters.

10. A composite ecological carrier for synergistic treatment of endogenous pollution in rivers and lakes—water purification—as described in any one of claims 1 to 9, characterized in that, The carrier system adopts a matrix-style modular layout. Each composite ecological carrier unit measures 2 meters by 3 meters. Adjacent units are connected by snap-fit ​​biodegradable connectors. The sediment seepage channels and aeration pipes of adjacent units are connected via waterproof quick-release joints, enabling modular connectivity of fluid pathways between units. Concrete counterweights are installed at the bottom of the in-situ sediment control matrix unit. These counterweights are secured to the four corners of the strip-shaped ecological bags with nylon ropes. Buoyancy-adjusting floats are installed along the edges of the surface floating plant symbiosis module. These floats are filled with hollow plastic buoys that can adjust buoyancy. After the entire carrier system is deployed, the strip-shaped ecological bags completely adhere to the surface of the river and lake sediment without any suspension. The modified artificial aquatic plant ribbons and water stratification purification modules are vertically distributed between the water surface and a depth of 3 meters underwater. The multi-source sensing and collaborative control unit is centrally located inside the shore control cabinet, which is connected to all underwater sensors and actuators via waterproof cables for power supply. After the carrier is deployed, indoor simulations and on-site enclosure tests are conducted simultaneously to verify the reduction effect of bottom sediment organic matter, nitrogen, phosphorus, and heavy metals, assess the ecological safety of the carrier for benthic organisms and aquatic plants, and test the structural integrity of the ecological bag and the functional decay law of the remediation agent under water flow scouring, alternating wet and dry conditions, and microbial aging. Based on the functional decay law, the effective service life of the carrier can reach 36 months.

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